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Nguyen Van Sa, Ph.D

Immunology Research Institute in Gifu, Japan

Specific Egg Yolk Antibody (Ovalgen DC) as a Novel Supportive Immunotherapy for

Dental Caries

Scientific conference at Vietnam National Hospital of Odonto-

Stomatology 2013

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S. mutans and dental caries

In-vitro tests

Animal tests

Human volunteer trials

Content

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WHO, 2003

Worldwide Dental Caries Level

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•Journal of pediatric Dentistry 44(1): 8-17, 2006

•Journal Dental Research 68, 1989

Streptococcus mutans (S. mutans) as

the main causative agent of dental caries

•S. mutans had a strong relation with dental

caries index (p < 0.01).

•The adherence of S. mutans to teeth surface

leads to a suitable environment for other

bacteria to grow.

Reference

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Cell-associated glucosyltransferase (CA-Gtase)

is the main pathogenic factor of S. mutans.

CA-GTase enzyme plays a vital role in

the pathogenicity of S. mutans

There are 2 kinds of GTase:

1.CF-GTase: produces soluble glucan

2.CA-GTase: produces insoluble glucan

Insoluble glucan strongly binds to teeth surface

and helps S. mutans to form colonies (plaques).

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S. mutans binds to tooth surface

Formation of Glucan by Gtase

Acids produced by S. mutans cause dental decay

Mechanism of Dental Caries

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Contains specific IgY against

Gtase enzyme of S. mutans

Ovalgen DC

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Mechanism of Ovalgen DC

Sucrose Glucan

GTase

Sucrose

Mode of effect

1. Inhibits S. mutans from attachment to tooth surface

2. Inhibits glucan formation by the bacterium

Ovalgen DC

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Comparison of various IgY on glucan

synthesis inhibition

IgY (mg/ml) 0.5 1.0 0

100

200

Glu

can s

ynth

esis

(%)

●：CA- GTase IgY

▲：CF- GTase IgY

□：Anti-fimbriae IgY

■：Anti-whole cell IgY

○：Control IgY

Infect. Immun. 1991, vol. 59

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PBS Anti-Gtase IgY

5mg/ml

Control IgY

5mg/ml

PBS Anti-Gtase IgY

5mg/ml

Control IgY

5mg/ml

Vortexing

Ovalgen DC blocks S. mutans from binding to teeth surface

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10μm 10μm

Electronmicroscopic image of S. mutans

grown in a medium containing sucrose

Without IgY With Ovalgen DC

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Animal tests

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Comparison of various antigens Test 1

(Infect. Immun. 1991, vol. 59)

2 days 52 days

Treatment with various IgY samples

Test group : IgY against various antigens

(0.8% in feed diet)

Control group : IgY derived from non-immune egg

Diet 2000, containing 56% sucrose

Infection with S. mutans

S. mutans RT8148 (1×10 8 cfu/rat )

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01020304050607080

Con

trol

anti-

Who

le C

ell

anti-

CA-G

Tase

anti-

CF-

GTas

e

Sha

m-im

mun

ed

Cari

es S

core

P<0.01 P<0.001

P<0.05 P<0.001

Results

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2 days 17 days

Groups

Test group : Ovalgen® DC 10mg/ml

Fluoride 10ppm

Control group : IgY derived from non-immune egg

Diet 2000, containing 56% sucrose

Test 2 Effect of Ovalgen® DC on Caries Development

in Rats

Infection with S. mutans

S. mutans RT8148 (1×10 8 cfu/rat )

(Joined research project with Karolinska Institute, Sweden)

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Treatment Total Smooth

Caries score

Total Sulcal

Caries score

Ovalgen® DC 43.0 ± 13.4

a) 40.9 ± 6.8

b)

Fluoride 54.6 ± 5.6 46.6 ± 3.0

Control 59.6 ± 14.3 48.5 ± 2.2

Results

a) p<0.001 and p<0.01 v.s. Fluoride and Control groups, respectively

b) p<0.01 v.s. Fluoride and Control groups

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Infected rats

Control Ovalgen DC

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Clinical trial on volunteers

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Clinical test 1: mouth wash test

Study at IRIG in Japan

4 volunteers taking part in a 2-phase test: in phase 1, a

placebo mouth wash was used. After 2 weeks, a mouth

wash containing Ovalgen DC was used. Plaque scores

were compared between 2 phases.

The volunteers did not brush teeth during the test.

2 weeks of break Placebo IgY 3d

Remove

plaques

Plaque

scoring

Ovalgen DC 3d

Remove

plaques

Plaque

scoring

No brushing No brushing

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Results

2

2.2

2.4

2.6

2.8

3

3.2

3.4

3.6

Placebo OVALGEN DC

Pla

qu

e S

core

s

Test 1

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Subjects: 99 student volunteers

- 2 test groups taking troches with OVALGEN DC

- 1 placebo group taking troches containing control

IgY

- 1 negative control untreated group

Test period: 5 days

– Volunteers used troches 5 times a day

– The test was carried out in a double blind manner.

Evaluation: S.mutans count score (by Mu-count kit)

Total anaerobic bacteria (by BHI medium)

Clinical test (Conducted at Hokkaido Medical College)

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Scoring by Mu-count kit

Score 0 Score 1 Score 2 Score 3 Score 4

Scoring method

CFU/kit Score

0 0

1-33 1

34-66 2

67-99 3

>100 4

Test 2

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0

0.5

1

1.5

2

2.5

3

Test 1 Test 2 Placebo Control

Before

After

Change in number of adherent S.mutans

Test 2

* *

*P < 0.001 by Wilcoxon

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Clinical trial results: Saliva S. mutans count

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Total anaerobic bacteria

Test 1 Test 2 Placebo Control

4.00

5.00

6.00

7.00

8.00

9.00

Lo

g1

0

CF

U/m

l

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Clinical Trial Result : Plaques

After

Before

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OVALGEN DC

Reduced number of S. mutans in saliva of human

volunteers

Did not affect normal flora in oral cavity

Is highly safe based on questionnaire result

Summary of human tests

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